In general, a part made of a resin such as a front ornamental panel of a large-sized television, an interior part of an automobile (for example, an audio panel or a door inner panel) or the like has a lustrous appearance surface as typified by a piano black lustrous appearance surface, and a resin is molded by injection molding into a highly lustrous appearance panel which is planar or substantially planar and which has a predetermined length and/or width.
Heretofore, such a highly lustrous appearance panel has been produced by injection molding by means of, for example, an injection molding die 101 as shown in FIG. 4.
In the injection molding die 101 shown in FIG. 4, a winkle gate 104 as a cold gate is provided at a tip of runners 102b which are in communication with a sprue 102a and which extend (in an interface) between a movable die member 103 and a fixed die member 106. As shown in FIG. 5, a plurality of the runners 102b are ramified from a runner branching point 102c, and the winkle gates 104 are provided at tips of the respective runners 102b. 
As shown also in FIG. 6, each of the winkle gates 104 is placed on a side of (proximate to) a rear surface 108b opposite to an appearance surface 108a of an ornamental panel 108 to be molded in a cavity 107 between the movable die member 103 and the fixed die member 106, a resin material is injected in a direction from the rear surface 108b toward the appearance surface 108a, i.e., the resin material is injected from the winkle gate 104 toward a molding surface of the fixed die member 106.
In the conventional injection molding die 101 shown in FIGS. 4 to 6, there is a problem that since volumes of the sprue 102a and the runners 102b are large, cost of their material is high. In addition, there are problems that appearance deficiency such as a flow mark is likely to be caused on the appearance surface 108a due to powdery resin which remained in the winkle gates 104, and that pressure loss is caused due to viscosity resistance when the molten resin is passed through the runners 102b and the winkle gates 104, and flow impediment is caused due to the pressure loss, and consequently, pressure distribution is non-uniform, and warp is thereby likely to occur to lead to difficulty in obtaining flatness.
In Patent Document 1, a method for molding an ornamental panel of a large-sized television which comprises injecting a resin material in a direction from an obverse surface to a reverse surface of a fitting rib to be molded in a molded product's reverse surface forming die part to permit a flow mark to occur on the reverse surface of the fitting rib or injecting a resin material from an edge of a top frame portion to be molded along a parting surface into a molding space orthogonal to a thickness direction of the ornamental panel of the large-sized television, thereby preventing a flow mark from occurring on an obverse surface of the ornamental panel of the large-sized television to enable black painting subsequent to the injection molding to be omitted.    Patent Document 1: Japanese Unexamined Patent Publication No. Hei-9 (1997) 267363